Adjusting screw lock for adjustable end wrenches



Sept. 14, 1954 T. F. JACKSON 2,638,893

ADJUSTING SCREW LOCK FOR ADJUSTABLE END WRENCHES Filed Aug. 1, 1952 l n/uanlr F Jackson Patented Sept. 14, 1954 UNITED STATES PATENT OFFICE ADJUSTING SCREW LOOK FOR ADJUSTABLE END WRENCHES Application August 1, 1952, Serial No. 302,143

2 Claims.

This invention relates to a new and improved adjusting screw lock for an adjustable end wrench.

It is well known that adjustable end wrenches, commonly called crescent wrenches, have long been subject to the objection that the movable jaw will not hold its adjustment, and there is consequently the need for repeatedly correcting the adjustment, which is both time-consuming and very annoying. Various constructions have been devised in an effort to solve this problem, but, so far as I am aware, none has been adopted commercially, and it is my belief that this is because they have been too complicated and expensive in construction in relation to the advantages olfered, and because they were not practical from the standpoints of dependability and positive action, and were not handy and speedy in operation in the un-locking and looking of the adjusting screw or worm when an adjustment has to be made. It is, therefore, the principal object of my invention to provide an adjustable end wrench which is designed to avoid so far as possible all of the objections mentioned and yet meet the various practical requirements enumerated.

The invention is illustrated in the accompanying drawings, in which- Figs. 1 and 2 are side views, taken from the opposite sides, of an adjustable end wrench made in accordance with my invention, a portion of the handle being broken off in Fig. 1;

Figs. 3 and 4 are longitudinal sections on the broken line 33 of Fig. 1, showing the wrench with the adjusting screw locked in Fig. 3 and unlocked in Fig. 4, and

Fig. 5 is a fragmentary side elevational view like a portion of Fig. 2 but showing a modified or alternative construction.

Similar reference numerals are applied to corresponding parts throughout the views.

Referring mainly to Figs. 1 to 4, the reference numeral 6 designates the handle of an adjustable end wrench, on the enlarged outer end portion of which is defined a head provided with the usual fixed jaw I and associated movable jaw B. The latter is slidably guided, as shown at 9, for adjustment transversely of the head and has rack teeth It along the inner edge meshing with the threads II of an adjusting screw I2 rotatably mounted on a pin I3 for manual operation in the usual way in a rectangular opening It provided in the head. The periphery of the threads II is usually knurled or roughened in some other way to provide a good finger grip surface to facilitate manual operation. In accordance with my invention, the screw I2, which may be knurled on the periphcry of its threads for a finger grip surface, has parallel grooves I5 cut in the threads in circumferentially spaced relation for locking engagement therein of a tooth I6 on the end of an elongated leaf spring I! provided by the inwardly bent outer end portion of said spring. The spring I! is disposed lengthwise of the handle and fastened at its inner end to the handle 6 by screws I8 and is normally bowed outwardly as appears in Fig. 3 and urges its toothed end It inwardly against the screw so as to engage in whichever groove I5 happens to be in register with the tooth, as shown in Fig. 3. Spring I1 is adapted to be flexed outwardly to the retracted position shown in Fig. 4 by means of a pin l9 that engages its inner side intermediate the ends thereof and is reciprocable in a hole 20 in the handle. A second elongated leaf spring 2I is disposed lengthwise of the handle on the opposite side from spring I! and is fastened at one end to the handle by a screw 22 and normally projects outwardly in acute angle relationship to the handle 6 with its free end spaced from the pin Is, as shown in Fig. 3, but is adapted to be flexed inwardly against the handle, as shown in Fig. 4, to press pin I9 inwardly and flex the spring I! outwardly to retracted position, so that the screw l2 can be turned to adjust jaw 8 in either direction. While spring 2I could conceivably be flexed inwardly by direct finger pressure, I prefer to provide for such operation a slide block or button 23 that is reciprocable in parallel guides 24 provided on the handle on opposite sides of the spring 2I by inwardly swedged flanges 25. The button 23 has a circular flange 26 of reduced thickness slidable freely in the guides in any position of rotation of the button, so that there is no danger of the button getting struck. The head of the screw 22 limits movement of the button 23 in one direction (see Fig. 3) and the end wall of the depression 21 in which the spring 2| and button 23 are disposed limits movement in the other direction. (See Fig. 4.)

If desired, a sheet metal plate 28 may be provided in lieu of flanges 25, as shown in Fig. 5, and be spot-welded to the handle 6, as indicated at 29. This plate provides a guideway between it and the handle 6' in depression 21 for the flange portion 26 of button 23, and the plate need only have an elongated slot 30 provided therein to receive the button and limit its travel. The operation with this construction is the same as with the other construction, because the depression 21 is deep enough to allow sufllcient outward flexing of spring 2| to permit spring I1 to effect locking engagement with screw 12.

In operation, the jaw 8 is adjusted by means of screw I2 while spring I! is held retracted by spring 2| and button 23, as in Fig. 4, and, after the desired adjustment has been made, button 23 is moved back again, as in Fig. 3, to permit the tooth IS on spring I! to engage in whichever groove [5 is in register with the tooth. If the tooth happens to abut the screw between grooves it will snap into one the instant the screw turns a trifle one way or the other in response to thrust transmitted to the screw from the jaw 8, after which no further change in wrench adjustment can possibly occur accidentally, or by manual operation of screw 12, until the screw I2 is unlocked again.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The a pended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. An adjustable end wrench comprising an elongated handle having an enlarged end portion terminating in a fixed jaw and having an opening provided therein, an adjustable jaw provided with a rack portion slidably mounted on said end portion, a screw rotatably mounted in said opening and meshing with said rack, an elongated fiat leaf spring disposed lengthwise of one side of said handle and fixed at one end to the handle and having the other end flexed outwardly but urged inwardly under inherent spring tension and having an inwardly bent edge portion on the extremity defining a tooth portion parallel to the axis of said screw and resil iently engaging the threads on said screw to pre- 4 vent rotation thereof, another elongated flat leaf spring disposed lengthwise of the other side of said handle and fixed at one end to the handle, the latter spring being bent intermediate its ends so that its free end projects normally away from the handle at an acute angle with respect to it, and a pin slidable in a hole provided in said handle engaging at its one end the free end portion of the second named leaf spring and at its other end a portion of the first named leaf spring intermediate the ends thereof, the second named leaf spring being adapted to be flexed inwardly toward the handle to cause the pin to flex the first named leaf spring outwardly away from said handle to a retracted position relative to said screw.

2. A wrench as set forth in claim 1, including a manually operable slider guided on said handle for movement lengthwise relative to said second named leaf spring and adapted to flex the outwardly bent free end portion of the latter inwardly toward the handle whereby to move said pin and flex the toothed free end portion of the first named leaf spring outwardly away from the handle to retracted position with respect to said screw.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,367,408 McClurkin Feb. 1, 1921 1,379,536 Davies May 24, 1921 1,512,846 Gumprecht Oct. 21, 1924 1,599,162 Brown Sept. 7, 1926 1,749,002 Schneider, et al Mar. 4, 1930 2,309,529 Orchard Jan. 26, 1943 2,316,455 Richardson Apr. 13, 1943 2,506,066 Coates May 2, 1950 

